Pre-election pendulum for the next Australian federal election

Last updated

The Australian Labor Party won the 2022 federal election, winning 77 of 151 seats in the House of Representatives. The Coalition holds 58 seats, and crossbenchers hold the remaining 16. [1] Following the 2023 Aston by-election, Labor gained a seat from the Liberal Party of Australia, increasing their seats in the House of Representatives to 78.

Contents

Classification of seats as marginal, fairly safe or safe is applied by the independent Australian Electoral Commission using the following definition: "Where a winning party receives less than 56% of the vote, the seat is classified as 'marginal', 56–60% is classified as 'fairly safe' and more than 60% is considered 'safe'." [2] Here, 'the vote' is defined as the vote after preferences, where the distribution of preferences has continued to the point where there are only 2 candidates left.

Pendulum

The Mackerras pendulum was devised by the Australian psephologist Malcolm Mackerras as a way of predicting the outcome of an election contested between two major parties in a Westminster style lower house legislature such as the Australian House of Representatives, which is composed of single-member electorates and which uses a preferential voting system such as a Condorcet method or instant-runoff voting.

The pendulum works by lining up all of the seats held in Parliament for the government, the opposition and the crossbenches according to the percentage point margin they are held by on a two party preferred basis. This is also known as the swing required for the seat to change hands. Given a uniform swing to the opposition or government parties, the number of seats that change hands can be predicted.

Government seats - 78
Marginal
Gilmore NSW Fiona Phillips ALP0.17
Lyons Tas Brian Mitchell ALP0.92
Lingiari NT Marion Scrymgour ALP0.95
Bennelong NSW Jerome Laxale ALP0.97
Higgins Vic Michelle Ananda-Rajah ALP2.06
Robertson NSW Gordon Reid ALP2.27
Tangney WA Sam Lim ALP2.37
McEwen Vic Rob Mitchell ALP3.24
Paterson NSW Meryl Swanson ALP3.27
Boothby SA Louise Miller-Frost ALP3.28
Aston Vic Mary Doyle [lower-alpha 1] ALP3.63
Hunter NSW Daniel Repacholi ALP4.08
Parramatta NSW Andrew Charlton ALP4.30
Blair Qld Shayne Neumann ALP5.23
Reid NSW Sally Sitou ALP5.24
Shortland NSW Pat Conroy ALP5.25
Dobell NSW Emma McBride ALP5.61
Werriwa NSW Anne Stanley ALP5.89
Hasluck WA Tania Lawrence ALP5.95
Fairly safe
Dunkley Vic Peta Murphy ALP6.27
Chisholm Vic Carina Garland ALP6.34
Bruce Vic Julian Hill ALP6.58
Isaacs Vic Mark Dreyfus ALP6.90
Holt Vic Cassandra Fernando ALP7.12
Hawke Vic Sam Rae ALP7.63
Corangamite Vic Libby Coker ALP7.64
Richmond NSW Justine Elliot ALP7.76
Macquarie NSW Susan Templeman ALP7.73
Eden-Monaro NSW Kristy McBain ALP8.09
Wills Vic Peter Khalil ALP vs. GRN8.53
Cooper Vic Ged Kearney ALP vs. GRN8.68
Macarthur NSW Mike Freelander ALP8.69
Hindmarsh SA Mark Butler ALP8.95
Pearce WA Tracey Roberts ALP8.98
Swan WA Zaneta Mascarenhas ALP8.99
Rankin Qld Jim Chalmers ALP9.09
Moreton Qld Graham Perrett ALP9.09
Solomon NT Luke Gosling ALP9.37
McMahon NSW Chris Bowen ALP9.49
Gorton Vic Brendan O'Connor ALP9.97
Safe
Whitlam NSW Stephen Jones ALP10.07
Lilley Qld Anika Wells ALP10.54
Cowan WA Anne Aly ALP10.79
Makin SA Tony Zappia ALP10.80
Gellibrand Vic Tim Watts ALP11.41
Greenway NSW Michelle Rowland ALP11.54
Oxley Qld Milton Dick ALP11.59
Adelaide SA Steve Georganas ALP11.91
Bendigo Vic Lisa Chesters ALP12.11
Canberra ACT Alicia Payne ALP vs. GRN12.20
Macnamara Vic Josh Burns ALP12.25
Jagajaga Vic Kate Thwaites ALP12.34
Maribyrnong Vic Bill Shorten ALP12.38
Calwell Vic Maria Vamvakinou ALP12.39
Lalor Vic Joanne Ryan ALP12.82
Spence SA Matt Burnell ALP12.90
Bean ACT David Smith ALP12.95
Ballarat Vic Catherine King ALP12.97
Corio Vic Richard Marles ALP13.01
Chifley NSW Ed Husic ALP13.36
Franklin Tas Julie Collins ALP13.70
Hotham Vic Clare O'Neil ALP14.25
Kingsford Smith NSW Matt Thistlethwaite ALP14.51
Cunningham NSW Alison Byrnes ALP14.70
Perth WA Patrick Gorman ALP14.80
Blaxland NSW Jason Clare ALP14.94
Burt WA Matt Keogh ALP15.21
Watson NSW Tony Burke ALP15.21
Barton NSW Linda Burney ALP15.54
Scullin Vic Andrew Giles ALP15.58
Fenner ACT Andrew Leigh ALP15.69
Kingston SA Amanda Rishworth ALP16.35
Sydney NSW Tanya Plibersek ALP vs. GRN16.56
Brand WA Madeleine King ALP16.71
Fraser Vic Daniel Mulino ALP16.73
Fremantle WA Josh Wilson ALP16.89
Grayndler NSW Anthony Albanese ALP vs. GRN17.06
Newcastle NSW Sharon Claydon ALP17.98
Opposition seats - 57
Marginal
Deakin Vic Michael Sukkar LIB0.19
Sturt SA James Stevens LIB0.45
Moore WA Ian Goodenough LIB0.66
Menzies Vic Keith Wolahan LIB0.68
Bass Tas Bridget Archer LIB1.43
Casey Vic Aaron Violi LIB1.48
Dickson Qld Peter Dutton LNP1.70
Cowper NSW Pat Conaghan NAT vs. IND2.32
Monash Vic Russell Broadbent LIB2.90
Longman Qld Terry Young LNP3.08
Banks NSW David Coleman LIB3.20
Bonner Qld Ross Vasta LNP3.41
Leichhardt Qld Warren Entsch LNP3.44
Canning WA Andrew Hastie LIB3.59
Nicholls Vic Sam Birrell NAT vs. IND3.81
Flynn Qld Colin Boyce LNP3.82
Wannon Vic Dan Tehan LIB vs. IND3.92
Bradfield NSW Paul Fletcher LIB vs. IND4.21
Forde Qld Bert Van Manen LNP4.23
Durack WA Melissa Price LIB4.27
Forrest WA Nola Marino LIB4.29
Petrie Qld Luke Howarth LNP4.44
Bowman Qld Henry Pike LNP5.51
Fairly safe
Lindsay NSW Melissa McIntosh LIB6.34
Capricornia Qld Michelle Landry LNP6.59
Flinders Vic Zoe McKenzie LIB6.70
Groom Qld Garth Hamilton LNP vs. IND6.89
O'Connor WA Rick Wilson LIB6.97
Hughes NSW Jenny Ware LIB7.01
Hume NSW Angus Taylor LIB7.72
Braddon Tas Gavin Pearce LIB8.03
Fisher Qld Andrew Wallace LNP8.67
La Trobe Vic Jason Wood LIB8.69
Fairfax Qld Ted O'Brien LNP8.97
McPherson Qld Karen Andrews LNP9.34
Calare NSW Andrew Gee [lower-alpha 2] NAT vs. IND9.68
Berowra NSW Julian Leeser LIB9.77
Safe
Grey SA Rowan Ramsey LIB10.07
Hinkler Qld Keith Pitt LNP10.07
Dawson Qld Andrew Willcox LNP10.42
Fadden Qld Stuart Robert LNP10.63
Mitchell NSW Alex Hawke LIB10.69
Page NSW Kevin Hogan NAT10.74
Wright Qld Scott Buchholz LNP10.89
Moncrieff Qld Angie Bell LNP11.19
Wide Bay Qld Llew O'Brien LNP11.34
Herbert Qld Phillip Thompson LNP11.77
Cook NSW Scott Morrison LIB12.44
Lyne NSW David Gillespie NAT13.80
Riverina NSW Michael McCormack NAT14.85
Farrer NSW Sussan Ley LIB16.35
New England NSW Barnaby Joyce NAT16.43
Barker SA Tony Pasin LIB16.62
Parkes NSW Mark Coulton NAT17.84
Mallee Vic Anne Webster NAT18.99
Gippsland Vic Darren Chester NAT20.57
Maranoa Qld David Littleproud LNP22.12
Crossbench seats - 16
Greens seats - 4
Marginal
Ryan Qld Elizabeth Watson-Brown GRN vs. LNP2.65
Brisbane Qld Stephen Bates GRN vs. LNP3.73
Safe
Melbourne Vic Adam Bandt GRN vs. ALP10.15
Griffith Qld Max Chandler-Mather GRN vs. LNP10.46
Other Crossbench - 12
Marginal
Curtin WA Kate Chaney IND vs. LIB1.26
Fowler NSW Dai Le IND vs. ALP1.63
Mackellar NSW Sophie Scamps IND vs. LIB2.50
Goldstein Vic Zoe Daniel IND vs. LIB2.87
North Sydney NSW Kylea Tink IND vs. LIB2.91
Kooyong Vic Monique Ryan IND vs. LIB2.94
Wentworth NSW Allegra Spender IND vs. LIB4.19
Fairly safe
Indi Vic Helen Haines IND vs. LIB9.08
Safe
Warringah NSW Zali Steggall IND vs. LIB10.92
Mayo SA Rebekha Sharkie CA vs. LIB12.27
Kennedy Qld Bob Katter KAP vs. LNP13.10
Clark Tas Andrew Wilkie IND vs. ALP20.82

Analysis

ABC psephologist Antony Green observed that due to the considerably expanded size of the crossbench following this election, the traditional two-column format of the Mackerras pendulum had become strained, and that the crossbench deserved more attention than its position at the bottom-right of the table suggested. [3]

Election analyst Ben Raue observed that the use of the two-party-preferred count in the Mackerras Pendulum also had the effect of classifying several seats as safer than they really were: for example, the seat of Macnamara ended up with a 12.25% margin of victory for the Labor candidate, but if just 0.64% of voters had changed their preference to rank the Greens higher than Labor, Labor would have finished third, with the Greens winning the seat by a similarly large margin. [4]

To overcome some of these limitations, the pollster Jim Reed produced a new Reed Pendulum after the 2022 election. [5]

This uses a two-candidate-preferred margin to classify each seat instead of a notional two-party preference count for the major parties, and has three arms so that contests involving minor parties and independent candidates are more clearly identified. One or two swing figures can be used to calculate seat changes along the arms.

Notes

  1. Mary Doyle was elected to Aston following a by-election in 2023 following the resignation of Alan Tudge.
  2. Andrew Gee resigned in 2022 to sit as an independent.

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The term swing refers to the extent of change in voter support, typically from one election or opinion poll to another, expressed as a positive or negative percentage point. For the Australian House of Representatives and the lower houses of the parliaments of all the states and territories except Tasmania and the ACT, Australia employs preferential voting in single-member constituencies. Under the full-preference instant-runoff voting system, in each seat the candidate with the lowest vote is eliminated and their preferences are distributed, which is repeated until only two candidates remain. While every seat has a two-candidate preferred (TCP) result, seats where the major parties have come first and second are commonly referred to as having a two-party-preferred (TPP) result. The concept of "swing" in Australian elections is not simply a function of the difference between the votes of the two leading candidates, as it is in Britain. To know the majority of any seat, and therefore the swing necessary for it to change hands, it is necessary to know the preferences of all the voters, regardless of their first preference votes. It is not uncommon in Australia for candidates who have comfortable leads on the first count to fail to win the seat, because "preference flows" go against them.

The Mackerras pendulum was devised by the Australian psephologist Malcolm Mackerras as a way of predicting the outcome of an election contested between two major parties in a Westminster style lower house legislature such as the Australian House of Representatives, which is composed of single-member electorates and which uses a preferential voting system such as a Condorcet method or IRV.

<span class="mw-page-title-main">Two-party-preferred vote</span> Result of election after distribution of preferences

In Australian politics, the two-party-preferred vote is the result of an election or opinion poll after preferences have been distributed to the highest two candidates, who in some cases can be independents. For the purposes of TPP, the Liberal/National Coalition is usually considered a single party, with Labor being the other major party. Typically the TPP is expressed as the percentages of votes attracted by each of the two major parties, e.g. "Coalition 50%, Labor 50%", where the values include both primary votes and preferences. The TPP is an indicator of how much swing has been attained/is required to change the result, taking into consideration preferences, which may have a significant effect on the result.

The following pendulum is known as the Mackerras pendulum, invented by psephologist Malcolm Mackerras. Designed for the outcome of the 2007 federal election, the pendulum works by lining up all of the seats held in Parliament, 83 Labor, 55 Liberal, 10 National, and 2 independent, according to the percentage point margin on a two candidate preferred basis, as elected in 2007. The two candidate result is also known as the swing required for the seat to change hands. Given a uniform swing to the opposition or government parties in an election, the number of seats that change hands can be predicted. Swing is never uniform, but in practice variations of swing among the Australian states usually tend to cancel each other out. Seats are arranged in safeness categories according to the Australian Electoral Commission's classification of safeness. "Safe" seats require a swing of over 10 per cent to change, "fairly safe" seats require a swing of between 6 and 10 per cent, while "marginal" seats require a swing of less than 6 per cent.

The following pendulum is known as the Mackerras pendulum, invented by psephologist Malcolm Mackerras. Designed for the outcome of the 2010 federal election, the pendulum works by lining up all of the seats held in Parliament, 72 Labor, 72 Coalition, 1 Nationals WA, 1 Green and 4 independent, according to the percentage point margin on a two candidate preferred basis. The two party result is also known as the swing required for the seat to change hands. Given a uniform swing to the opposition or government parties in an election, the number of seats that change hands can be predicted. Swing is never uniform, but in practice variations of swing among the Australian states usually tend to cancel each other out. Seats are arranged in safeness categories according to the Australian Electoral Commission's classification of safeness. "Safe" seats require a swing of over 10 per cent to change, "fairly safe" seats require a swing of between 6 and 10 per cent, while "marginal" seats require a swing of less than 6 per cent.

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The following is a pendulum based on the outcome of the 2010 federal election and changes since, including the redistributions of seats in South Australia and Victoria. It is a Mackerras pendulum, invented by psephologist Malcolm Mackerras, which works by lining up all of the seats held in Parliament according to the percentage point margin on a two-candidate-preferred basis. The two-party result is also known as the swing required for the seat to change hands. Given a uniform swing to the opposition or government parties in an election, the number of seats that change hands can be predicted. Swings are never uniform, but in practice variations of swing among the Australian states usually tend to cancel each other out. Seats are arranged in safeness categories according to the Australian Electoral Commission's (AEC) classification of safeness. "Safe" seats require a swing of over 10 per cent to change, "fairly safe" seats require a swing of between 6 and 10 per cent, while "marginal" seats require a swing of less than 6 per cent. The swings for South Australian and Victorian seats are notional, based on calculations by the AEC.

At the 2016 federal election of the 150 House of Representatives seats the Liberal/National Coalition won 76, a one-seat majority, Labor won 69 seats and crossbenchers won the remaining five. A redistribution in 2017/18 changed the representation entitlements. For the next election, the number of seats in the House will increase to 151, South Australia will lose a seat, Victoria and the Australian Capital Territory (ACT) will gain one seat each.

The following pendulum is known as the Mackerras pendulum, invented by psephologist Malcolm Mackerras. Based upon the outcome of the 2007 federal election and changes before the 2010 election, the pendulum works by lining up all of the seats held in Parliament, 83 Labor, 55 Liberal, 9 National, and 3 independent, according to the percentage point margin on a two party preferred basis.

The Coalition won the 2013 federal election with 90 of 150 lower house seats on a current 17-seat, 3.65-point two-party swing, defeating the 6-year Labor government. Labor holds 55 seats while crossbenchers hold the remaining five. The Division of Fairfax was the last seat to be declared.

This is a Mackerras pendulum for the 2016 Australian federal election.

The Coalition won the 2016 federal election with a one-seat majority 76 of 150 lower house seats. Labor holds 69 seats while crossbenchers hold the remaining five.

The Labor party won the 2018 state election by winning 55 of the 88 lower house seats. The coalition won 27 seats while the Greens and independents won 3 each.

The Coalition won the 2019 federal election with a three-seat majority of 77 of 151 lower house seats. Labor holds 68 seats, and crossbenchers hold the remaining six.

The Mackerras pendulum was devised by the Australian psephologist Malcolm Mackerras as a way of predicting the outcome of an election contested between two major parties in a Westminster style lower house legislature such as the Australian House of Representatives, which is composed of single-member electorates and which uses a preferential voting system such as a Condorcet method or IRV.

The Australian Labor Party won the 2022 federal election, winning 77 of 151 seats in the House of Representatives. The Coalition holds 58 seats, and crossbenchers hold the remaining 16.

The Mackerras pendulum was devised by the Australian psephologist Malcolm Mackerras as a way of predicting the outcome of an election contested between two major parties in a Westminster style lower house legislature such as the Australian House of Representatives, which is composed of single-member electorates and which uses a preferential voting system such as a Condorcet method or instant-runoff voting.

References

  1. "Seat summary". AEC Tally Room. Australian Electoral Commission. Retrieved 27 May 2022.
  2. Division Classifications, Virtual Tally Room 2016, Australian Electoral Commission. Retrieved 21 August 2016.
  3. Antony Green (19 June 2022). "2022 Post-Federal Election Pendulum". Antony Green's Election Blog. Retrieved 29 June 2022.
  4. Ben Raue (27 June 2022). "Understanding 3CP trends". The Tally Room. Retrieved 29 June 2022.
  5. Jim Reed (13 June 2022). "2022 Post-Federal Election Reed Pendulum" (PDF). Resolve Strategic. Retrieved 8 July 2022.